Summation.

[STEP II 2011 Question 7 (Pure)]

Difference equations, proof by induction, geometric progression, period of sequences.

[STEP III 2005 Question 4 (Pure)]

Difference equations, sequence, proof, period of sequences, C1-ish.

[STEP III 2004 Question 6 (Pure)]

Sequence, strictly increasing, inequality, proof, C1.

[STEP I 2004 Question 8 (Pure)]